• Title/Summary/Keyword: Emission unit

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Study on Emission Characteristics in a Hydrogen-fueled Engine (수소기관에서의 배기가스에 관한 연구)

  • Cho, U.L.;Ghoi, G.H.;Bae, S.C.
    • Transactions of the Korean hydrogen and new energy society
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    • v.13 no.1
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    • pp.83-89
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    • 2002
  • The goal of this research is to understand the NOx emission in direct injected diesel engine with premixed hydrogen fuel. Hydrogen fuel was supplied into the test engine through the intake pipe. Amount of hydrogen-supplemented fuel was 70 % basis on heating value of the total input fuel. The effects of intake air temperature and exhaust gas recirculation(EGR) on NOx emission were studied. The intake air temperatures were varied from $23^{\circ}C$ to $0^{\circ}C$ by using liquid nitrogen. Also, the exhaust gas was recirculated to the intake manifold and the amount of exhaust gas was controlled by the valve. The major conclusions of this work include: ( i ) nitrogen concentrations in the intake pipe were increased by 30% and cylinder gas temperature was decreased by 24% as the intake air temperature were changed from $23^{\circ}C$ to $0^{\circ}C$; ( ii ) NOx emission per unit heating value of supplied fuel was decreased by 45% with same decrease of intake air temperature; and (iii) NOx emission was decreased by 77% with 30% of EGR ratio. Therefore, it may be concluded that EGR is effective method to lower NOx emission in hydrogen fueled engine.

A new model and testing verification for evaluating the carbon efficiency of server

  • Liang Guo;Yue Wang;Yixing Zhang;Caihong Zhou;Kexin Xu;Shaopeng Wang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.10
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    • pp.2682-2700
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    • 2023
  • To cope with the risks of climate change and promote the realization of carbon peaking and carbon neutrality, this paper first comprehensively considers the policy background, technical trends and carbon reduction paths of energy conservation and emission reduction in data center server industry. Second, we propose a computing power carbon efficiency of data center server, and constructs the carbon emission per performance of server (CEPS) model. According to the model, this paper selects the mainstream data center servers for testing. The result shows that with the improvement of server performance, the total carbon emissions are rising. However, the speed of performance improvement is faster than that of carbon emission, hence the relative carbon emission per unit computing power shows a continuous decreasing trend. Moreover, there are some differences between different products, and it is calculated that the carbon emission per unit performance is 20-60KG when the service life of the server is five years.

A High Aperture Ratio TFT Design for Bottom Emission Type AMOLED

  • Chien, Yao Hong;Huang, Jack
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.711-714
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    • 2004
  • A new design for improving the aperture ratio of bottom emission type AMOLED is investigated. In conventional, the TFT of AMOLED fabrication method is "Etch Stopper (7-mask)", so the aperture ratio is limited in 28${\sim}$33% by Cs(Storage Capacitor). A high aperture ratio TFT is designed by using BCE(Back Channel Etching 5-mask) fabrication way and the aperture ratio is up to 40% shown in 2.2"AMOLED display.

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LIfe Cycle Assessment(LCA) for Calculation of the Carbon Emission Amount of Organic Farming Material -With Oyster-shell, Expanded Rice Hull, Bordeaux Mixture Liquid- (유기농자재의 탄소배출량 산정을 위한 전과정평가(LCA) -패화석, 팽연왕겨, 보르도액을 중심으로-)

  • Yoon, Sung-Yee;Yang, Dong-Wook
    • Korean Journal of Organic Agriculture
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    • v.20 no.4
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    • pp.475-490
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    • 2012
  • Since 1997, Korean Ministry of Knowledge Economy and Ministry of Environment have established data on some 400 basic raw and subsidiary materials and process like energy, petro-chemical, steel, cement, glass, paper, construction materials, transportation, recycling and disposal etc by initiating establishment of LCI database. Regarding agriculture, Rural Development Administration has conducted establishment of LCI database for major farm products like rice, barley, beans, cabbage and radish etc from 2009, and released that they would establish LCI database for 50 items until 2020 later on. The domestic LCI database for seeds, seedling, agrochemical, inorganic, fertilizer and organic fertilizer etc is only at initial stage of establishment, so overseas LCI databases are brought and being used. However, since the domestic and overseas natural environments differ, they fall behind in reliability. Therefore, this study has the purpose to select organic farming materials, survey the production process for various types of organic farming materials and establish LCI database for the effects of greenhouse gas emitted by each crop during the process. As for selecting methods, in this study organic farming materials were selected in the method of direct observation of material and bottom-up method a survey method with focus on the organic farming materials admitted into rice production. For the basic unit of carbon emission amount by the production of 1kg of organic farming material, the software PASS 4.1.1 developed by Korea Accreditation Board under Ministry of Knowledge Economy was used. The study had the goal to ultimately provide basic unit to calculate carbon emission amount in executing many institutions like goal management system and carbon performance display system etc in agricultural sector to be conducted later on. As a result, emission basic units per 1kg of production were calculated to be 0.04968kg-$CO_2$ for oystershells, 0.004692kg-$CO_2$ for expanded rice hull, and 1.029kg-$CO_2$ for bordeaux mixture liquid.

MACT Application Effect in Petrochemical Industry to Minimize Benzene Fugitive Emission (석유화학산업의 벤젠 비산배출 저감을 위한 MACT 적용효과)

  • Kim, HunJang;Moon, Jinyoung;Hwang, Yongwoo;Kwak, Inho
    • Journal of Korean Society of Environmental Engineers
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    • v.38 no.8
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    • pp.435-443
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    • 2016
  • In this study, MACT (Maximum Achievable Control Technology) application effect was evaluated for minimization of benzene fugitive emission in petrochemical industry. Although fugitive emission for benzene in the nation was regulated by the Clean Air Conservation Act from 2015, the US EPA already has introduced MACT standard to minimize its emission with up-to-date technology since 1995. EPA Emission Factor (AP-42) and EPA MACT Standard Guideline were used to assess MACT application effect. As a result, For MACT application it could reduce benzene emission up to 98% (average) comparing with uncontrolled facility, while the national regulation could achieve about 95% (average) reduction which is slightly lower than MACT. However there is no control measure in the national regulation to reduce benzene emission for vessel loading even though MACT standard requires preventive facility such as VRU (Vapor Recovery Unit). For further reduction of benzene emission, it needs to be mandatory for operation of VRU when benzene product is loaded in vessel. These efforts could contribute to achieve the global level for benzene emission management in national petrochemical industry.

Application of Input-Output Table to Estimate of Amount of Energy Consumption and CO2 Emission Intensity in the Construction Materials -Focusing on Input-Output Tables Published in 2005, 2007- (건축공사 주요자재별 에너지소비량 및 CO2 배출 원단위 값 산출에 산업연관표 적용 적정성 검토 연구 -2005년, 2007년 산업연관표를 중심으로-)

  • Jung, Young-Chul;Kim, Sung-Eun;Jang, Young-Jun;Kim, Tae-Hui;Kim, Gwang-Hee
    • Journal of the Korea Institute of Building Construction
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    • v.11 no.3
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    • pp.247-255
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    • 2011
  • Currently, there is database for per unit requirements of major construction materials in terms of energy consumption and $CO_2$ emission based on the input-output table published by the Bank of Korea in 2000, but no database for per unit requirements based on input-output tables was published in 2005 and 2007. The purpose of this study was to calculate the unit requirement values of major construction materials in terms of energy consumption and $CO_2$ emission generated by using the input-output tables published in 2005 and 2007. To estimate the unit requirement values, a database building method with the input-output tables was adopted by selecting 16 types of construction materials in wide use on construction sites. When the study results were compared with existing unit requirement values based on the input-output table of 2000, there were small discrepancies, from which it can be interpreted that the method used in the study is reasonable. Unit requirement values estimated based on input-output tables of 2005 and 2007 tended to decrease, and the highest value of energy consumption and $CO_2$ emission were found in the materials using cement and rebar.

A Review on the Emission Sources of Ammonia and the Factors Affecting Its Loss

  • Das, Piw;Sa, Jae-Hwan;Kim, D.S.;Kim, K.H.;Jeon, E.C.
    • Journal of Korean Society for Atmospheric Environment
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    • v.23 no.E2
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    • pp.47-56
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    • 2007
  • Among all the nitrogen species present in the atmosphere, ammonia forms a considerable portion along with the nitrogen oxides. The major sources of atmospheric ammonia are animal feedlot operations including emission from excreta of domestic animals and agricultural activities, followed by emission from synthetic fertilizers, biomass burning and to some lesser extent, fossil fuel combustion. Ammonia emission factor, expressed as the weight of ammonia per unit weight, volume, or duration of the activity emitting it, is generally used in developing emission estimates for emission inventories. The factors determining ammonia loss from soil or from manures are the temperature, pH, humidity, precipitation and the velocity of wind above it.

Methane Emissions from Dry Cows Fed Grass or Legume Silage

  • Kasuya, Hirotaka;Takahashi, Junichi
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.5
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    • pp.563-566
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    • 2010
  • Using an open-circuit system, we compared the methane ($CH_4$) emission from dry cows fed first-cut Timothy silage ($1^{st}$ TY), second-cut Timothy silage ($2^{nd}$ TY), second-cut Italian ryegrass silage ($2^{nd}$ IR), third-cut Italian ryegrass silage ($3^{rd}$ IR), or second-cut red clover silage ($2^{nd}$ RC) as the sole feed. The methane emission ranged from 258.2 L $day^{-1}$ to 396.5 L $day^{-1}$. The methane emission from dry cows fed red clover silage was relatively lower than that from dry cows fed grass silage. However, the methane emission per unit digestible neutral detergent fiber (NDF) intake (dNDFI) did not differ significantly between the experimental silages. The methane emission was significantly correlated with the NDF intake and digestibility. Methane emission had a significant correlation with the quadratic function of dNDFI. The differences in the daily volume of methane emission from cows fed different forages can be explained by dNDFI.

Development of Low NOx Gas Burner Absorption Chiller/Heater Unit (흡수식 냉온수기용 저 NOx 가스버너 개발)

  • 최정환;오신규
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.1
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    • pp.277-283
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    • 1995
  • For the development of low NO$_{x}$ gas burners aimed for absorption chiller/heater unit, three proto type burners of different capacity (265000, 498000, and 664000 kcal/h) have been manufactured through a combustion method of step-by-step air injection. In order to characterize the overall features of the flame and the properties of the emission gas, the temperature of the flame and the concentration of NO$_{x}$ and CO were determined. The main factors in the design of burners (the area of primary air injection, the diameter of secondary air injection hole, fuel nozzle diameter) were observed to increase linearly with the scale-up of burner capacity. The flame temperature profiles of the burners were observed to be almost similar, irrespective of their capacity. However, as their capacity increased, the flame temperature slightly increased and the hot region of the flames moved to ward the flame tip along with the expansion to the direction of radius. From the proto type units, the amount of their NO$_{x}$ emission was determined to be around 25 - 30 vppm(3% )$_{2}$) and the CO emission was less than 19 vppm (3% $O_{2}$).TEX>).

Field Emission-Back Light Unit Fabricated Using Carbon Nanotube Emitter

  • Kim, H.S.;Lee, J.W.;Lee, S.K.;Lee, C.S.;Jung, K.W.;Lim, J.H.;Moon, J.W.;Hwang, M.I.;Kim, I.H.;Kim, Y.H.;Lee, B.G.;Choi, Y.C.;Seon, H.R.;Lee, S.J.;Park, J.H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.277-280
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    • 2007
  • Field emission-back light unit (FE-BLU) was fabricated using carbon nanotube (CNT) emitter. Local dimming and local brightening techniques were achieved, which results in very high contrast ratio. In addition, the motion blur phenomenon, one of the serious problems of liquid crystal display (LCD) with cold cathode fluorescent lamp (CCFL)-BLU, was removed from LCD-TV by using FE-BLU.

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